Storage systems are conventionally used which replicate received data received from clients or the like and store respectively the replicated received data in different storages. In such storage systems, since the same received data is stored in a plurality of storages, it is possible to reduce a probability that the received data may be lost.
However, with the conventional storage systems, combinations of storages that store the same received data and allocation ratios of the received data corresponding to the respective combinations are fixed. For this reason, when a failure probability of a combination as a whole increases due to an increase of a frequency of use or an energizing time, the received data stored in the combination may be lost.